Time-of-flight measurement of the evaporation residues from fusion of 5.9 mev/u 84kr and 27al

Abstract

Mass and Z-distributions of the evaporation residues from compound-nucleus formation in the reaction 5.9 MeV/u 84Kr on 27Al were measured using a time-of-flight ΔE − E telescope, which is described in detail. The high recoil velocity attained by choosing the heavy reaction partner as projectile made it possible to resolve the reaction products by mass and atomic number. Data were taken in the angular range from 1.5 to 6°. The residue distributions are compared to evaporation calculations assuming the statistical decay by fission and particle evaporation of the compound nucleus 111Mn formed at an excitation energy of 108 MeV with angular momenta up to L CN ≈ 69 h ̵ . The data are consistent with the assumption of statistical equilibrium. Details of the de-excitation process, in particular the fission competition and the influence of nuclear deformations at high angular momenta, are discussed.